Synthetic hydrocarbon oils and process of producing same



Dec. 10, 1940- M. M. HOLM ETI'AL 3 SYNTHETIC HYDROCARBQN OILS ANDPROCESS OF PRODUCING SAME Filed Dec. 31, 1934 2 Sheets-Sheet l .m amEo NV m 5 8 c m 3 w. Edna S w l 2 5256 295$ 5; 26

Inventors Melvin M. Ho/m Arfhur L. Lyman Marv/h F. Miller 223 50 ,8ozzkmah 2.535

M. M. HOLM ET AL.

Dec. 10, 1940.

Filed Dec. 31, 1934 2 Sheets-Sheet 2 mdwizoa m= .255 H s um 8 4 I 1M mmmm [Inn Nm nun s 5 mm 3 8 2mm a W /JM mML Er mm 3565 H E232 -85 H q J 573 Q Q mu om ,H 8 3 25m m 8 Patented Dec. 10,1940

UNITED STATES azzem PATENT OFFICE SYNTHETIC HYDBOCABBON OILS-AND PROCESSOF PRODUCING SAME Application December 31, 1934, Serial No. 759,960

Claims.

This invention relates to synthetic hydrocarbon oils of high viscosityand high viscosity index, and to processes of producing the same fromgaseous or low boiling oleiinic hydrocarbons. More par- 5 ticularly, itrelates to the catalytic polymerization v of gaseous or low boilingpoint oleflnes under such conditions as will result in the production ofoleflnic polymers of high viscosity and high viscosity index. Further,it relates to the hydrol genation of the high viscosity. high viscosityindex oleflnlc polymers produced, and to the saturated hydrocarbons,likewise of high viscosity and high viscosity index, prepared by suchhydrogenation.

l Ordinarily, gaseous or low boiling oleflnes are polymerizable toproducts of only relatively low viscosity; moreover, these gaseous orlow'boiling oleflnes are generally polymerizable to products of quitelow viscosity index, This process differs from the prior processes inthat olefinic polymers of extremely high viscosity and of extremely highviscosity index are prepared from such low boiling or gaseous olefinichydrocarbons, and, moreover, differs from the prior processes in that itmakes use of both normal or straight chain oleflnes and iso or branchedchain olefines in the preparation of such products. The productsresulting from the process of the invention are characterized by noveland useful properties not possessed by the 0 known prior products, andnew and useful functions are performed by their employment.

It is accordingly a purpose of our invention to disclose and providesynthetic hydrocarbons of high viscosity and high viscosity index, andto disclose and provide processes of preparing the same from low boilingoleflnes and mixtures of low boiling olefines. It is a further purposeof the invention to disclose and provid processes of preparing synthetichydrocarbons of high viscosit? and high viscosity index from low boilingoleflne mixtures containing both normal and iso oleflnes. It is afurther purpose of our invention to disclose and provide water-white,crystel-clear products of high viscosity index and of viscosity of anydesired range, from moderate to extremely high viscosity, as desired,suitable for a wide variety of technical uses and possessing novel anduseful properties. It is a further purpose of the invention to discloseprocesses of producing sulfur-free oleflne polymers of extreme purity,capable of hydrogenation to produce saturated, stable hydrocarbons ofnovel and unusual characteristics.

In general, the process of this invention comprises segregating from itssource material the reaction, the concentrationof unreacted oleflnesin'the mixture undergoing polymerization, and the relative proportionsof normal oleflnes to iso 15 oleflnes; removing from the polymerizationreaction mixture substantially completely all reaction products otherthan inert hydrocarbons and polymerized oleflnes themselves; andseparating from the mixture by distillation any desired fraction, 20according to the particular requirements of the material ultimatelydesired, as to viscosity, volatility and the like. If desired, eitherthe whole mixture of polymers or any fraction thereofis thenhydrogenated to obtain a series of saturated hydrocarbons of extremepurity and likewise of high viscosity and high viscosity index.

As source materials for the. low boiling olefines found suitable for thepractice of this invention, we make use of the oleilne-containing gasesgenerally produced in the thermal cracking of petroleum crude oils,distillates, or residuum, although it will be apparent that otheroleflne-containing materials serve as well. These petroleum crackingstill gases contain considerable quantities of oelflnic materials, fromethylene and propylene up to and through the pentenes, according to thetemperature and pressure under which the liquid products of theconversion operation are con- 0 densed. These oleflne-containingcracking still gases are often fractionated for the recovery of certainof their constituent hydrocarbons, and we prefer to make use of thosefractions or cuts containing the maximum economically available pro- 5portion of the four-carbon atom oleflnes, namely, butene-1, butene-2 andisobutene. Such fractions contain large amounts, generally, of saturatedhydrocarbons of similar boiling points and the butene fractions referredto ordinarily con- 50 tain considerable quantities of butane. Otherhydrocarbons, both saturated and unsaturated, are present in lesseramounts, and the presence of ethylene, propylene and the pentenes, inlesser amounts, together with their associated saturated 5|hydrocarbons, is of no detriment to the operation of our process. I

We have found, in general, that while propylene provides suitablepolymers according to our invention, it requires the use of considerablylarger amounts of the polymerization catalyst,

and that the pentenes while not objectionable, react underpolymerization conditions much slower than do the butenes, and,moreover, tend to produce products of lower viscosity and lowerviscosity index than are the products prepared from the butenes.

The saturated hydrocarbons ordinarily accompanying the olefines producedin a thermal conversion reaction, as above, while inert, have been foundextremely desirable constituents of the olefine mixture undergoingpolymerization, and we make no effort to segregate saturated fromunsaturated hydrocarbons except in the somewhat unusual event thatolefines are present in the source material only .in extremely smallquantities. As discussed more fully below, use is made of theseaccompanying saturated hydrocarbons to aid in the control of thetemperature of the polymerization reaction, and their presence isdesired for this reason.

The relative proportion of normal and iso olefines in the sourcematerial has been-found of considerable consequence to the properties ofthe composiionl prepared, and we provide below a full discussion of theeffect of this variable, together with the means of taking advantage ofvariations in the proportions of these racting substancs.

In the event that the gases from a petroleum conversion operation areutilized as a source material for the low boiling point olefinescontemplated to be polymerized, we take particular precautions to removeall sulfur and all sulfurcontaining compounds therefrom prior to theolefine polymerization reaction. Ordinarily, small quantities ofhydrogen sulfide and low boiling mercaptans are present in such gaseousmixtures, and we find that serious consequences result if these andother sulfur compounds are not removed. In particular, we have foundthat the life of the polymerization catalyst is relamercaptides (theconventional tively short and that the consumption of the hydrogenationcatalyst, if the composition be ultimately hydrogenated, is extremelyhigh, if the said sulfur compounds are not substantially entirelyremoved.

These sulfur compounds may be removed by a careful treatment with anaqueous alkaline hydroxide, such as sodium hydroxide, with which bothhydrogen sulfide and the lower mercaptans react to form water-solubleproducts; or they may be removed by a careful treatment with sodiumplumbite solution followed by the addition of elemental sulfur todecompose produced "doctor" treatment) followed by careful vaporizationof the sulfur-free hydrocarbons from the produced disulfides whichremain as a residue; or by a combination treatment in which sodiumhydroxide is used to reduce the hydrogen sulfide and mercaptan contentto a minimum, followed by a plumbite treatment to remove the last tracesthereof.

The sulfur-free olefinic material is, prior to subjection topolymerizing conditions, preferably thoroughly dried, and freed'not onlyof all traces of entrained water, but also of substantially all of itsdissolved water. We have found that traces of water, even of the orderof the 0.02% by weight thereof which remains in clear and homogeneou ssolutionat ordinary temperatures, is extremely detrimental not only tothe consumption of polymerization catalysts, but, more particularly,that it is the cause of two very undesirable side reactions during thepolymerization reaction: first, itcauses the formation of minute amountsof hydrochloric acid and ultimately of minute amounts of chlorinatedhydrocarbons, undesirable not only in the olefinic composition of highviscosity and high viscosity index, but more especially undesirable inthe event form a completely saturated composition; second, the presenceof even dissolved water causes the formation of color bodies which aredifflcult or impossible to remove after their formation, either from theoleflnic hydrogenated compositio This dissolved water may be removed byany ordinary means, such as by percolation through calcium oxide orcalcium chloride, by freezing out at low temperatures, etc., of whichseveral alternative methods we prefer treatment with anhydrous calciumchloride by reason of the ease of handling both the charged and spentagent and by reason of the relatively low cost of such an operation.

The sulfurt-free water-free oleflnic material,

preferably largely a butene containing material,

is now subjected to a polymerization reaction, and as a polymerizationcatalyst we generally make use of anhydrous aluminum chloride, by reasonof its relatively low cost and of the ease of controlling thepolymerization reaction itself.

This polymerization reaction is preferably, although not in all casesnecessarily, carried out at temperatures slightly below atmospheric. Wehave found that temperatures excessively below atmospheric are of noparticular benefit to the practice of our invention, and we employordinarily a temperature within the range F. to 40 to 80 F., dependingsomewhat upon the character of temperature control employed and likewiseto some extent upon the proportion of normal olefines to iso olefineswhich exist in the olefine-containing mixture utilized. A fulldiscussion of the effect of temperature, with which are related theeffect of olefine concentration in the mixture undergoing polymerizationand the eifect of the proportions of normal and iso olefines existing inthe mixture, is provided herein below, and it this point it will besuflicient merely to point out that for the production of high viscosityand high viscosity index olefine polymers: first, the temperature of thepolymerization reaction may be allowed to go to 80 F. or even higher ifthe olefine concentration of the source material is relatively high, butit must be=kept lower, say to 30 to 40 F. if the olefine concentrationof the source material is relatively low; second, the temperature of thepolymerization reaction must be kept relatively low, say to 30 to 40 F.or even lower, if the ratio of normal olefines to iso olefines isrelatively high.

The first of these variables may be suitably regulated by therecirculation of unreacted inert saturated hydrocarbons such as butane,back to and through the polymerization reaction chamber prior to entryto the polymerization reaction chamber, as shown below.

The temperatures obtaining during the preliminary reaction itself may becontrolled bya variety of means, among which may be mentioned:refrigeration prior to entry to the polymerization reaction chamber of adegree suflicomposition or from a ,that the olefinic composition ishydrogenated to cient to allow for the maximum permissible temperaturedue to reaction; removal of heat of reaction by external refrigerationduring the polymerization reaction; division of the polymerizationreaction chamber into two or more separate units, in series, withprovision for refrigeration between such units; and dilution of thereacting materials with inert materials such as saturated hydrocarbons.recycled saturated hydrocarbons, or recycled products of reaction, bywhich the heat of reaction is distributed and adequately absorbed. Ofthe olefines undergoing polymerization, iso butane, or, more generally,the iso olefines, are the most reactive, and it is therefore importantthat the early stages of the polymerization be effected under conditionswhich permit careful control of the temperature of reaction.

The anhydrous aluminum chloride catalyst chamber may be of any desiredshape or character, and may suitably be packed with lump or granularanhydrous aluminum chloride over and through which theoleflne-containing material may pass. We have found it convenient topass theoleflne-containing material downwardly, in

liquid form, through a chamber packed with a technical, unsized grade ofanhydrous aluminum chloride, and to allow the products of reaction,-both the oily hydrocarbon liquid containing dissolved produced polymersand the liquid aluminum chloride sludge which results,to leave through asingle outlet at the bottom of the chamber. then settled in a settlingchamber, to free the hydrocarbon liquid of entrained sludge," which isto all intents and purposes useless for further production of polymersof the desired character. The anhydrous aluminum chloride necessary tothe polymerization reaction is added to the chamber continuously orintermittently. generally the latter, for convenience, for we have foundthat the presence of considerable excess quantities of aluminum chloridecatalyst is of no effect in modifying the character of the polymersproduced; as used up or "spent the catalyst liquefles into a sludge ofbut little further catalyzing power, and is removed from the sphere ofaction in any desired manner.

The complete removal of all entrained aluminum chloride sludge from thepolymers, or from the polymer-containing hydrocarbon liquid, has beenfound of extreme importance for the production of colorless products,whether oleflnic or saturated by a subsequent hydrogenation step.Complete settlement in an open or unpacked vessel is satisfactory, ifsuillcient time is allowed; in order to insure complete and rapidremoval of entrained sludge we generally employ, however, a chamberpacked with a crushed rock,or other mineral substance which is inert tothe materials passing therethrough and which is ground or crushed tosuitable particle size to provide large surfaces on which the sludge maycoalesce without, at the same time, causing unnecessarily large pressuredrop through the chamber.

As a subsequent clarification step, the polymercontaining liquid ispassed through an adsorbent agent such as Florida clay, charcoal or thelike, both to insure positively complete removal of all entrainedaluminum chloride sludge and also to entirely remove all color-formingbodies which exist in the mixture by virtue of the polymerizationreactions just completed. In particular, we

avoid the use of water to remove the aluminum chloride sludge, whetheradded as such or as This mixture of immiscible liquids is steam in anysteam distillation step, for such water hydrolyzes or reacts with evenextremely small quantities of the sludge to produce color bodies whichare soluble in the hydrocarbon oils and are difilcult or impossiblesubsequently to remove. Coincident with the formation of color bodies byhydrolysis of the aluminum chloride sludge, small amounts ofhydrochloric acid and of aluminum hydroxide are formed. Chlorinatedhydrocarbons result from the presence of hydrochloric acid, and thealuminum hydroxide, while inert chemically, is extremely dimcult toremove in the preparation of a permanently clear and ash-free oil. Thepassage of the polymer-containing liquid through an adsorbent materialsuch as a granular Florida or equivalent earth, activated carbon, etc.,satisfactorily obviates the possible appearance of color bodies in thepolymers ultimately segregated, and after such filtration or percolationwater or steam may be allowed to come into contact with the polymers, orthey may be distilled under all ordinary conditions, without hazard.

The liquid stream leaving the filtering or percolation chamber consistsof oleflne polymers of high viscosity and high viscosity index, dilutedwith the inert saturated hydrocarbons originally accompanying thegaseous or low boiling olefines; it may contain, in addition, smallquantities of unpolymerized low boiling olefines if the time of contactof the olefines with the polymerizing catalyst be insuillcient to eifectcomplete utilization of the original olefines. If the originalolefinecontaining material is a butene-butane fraction or cut from apetroleum conversion still gas, the liquid stream consistsessentially'of heavy polymers diluted with butane.

The butane and accompanying low boiling hydrocarbons are separated fromthe heavy olefine polymers by any ordinary vaporization process, such asa flash distillation, in which the polymers are obtained as a residueand in which butane appears in vapor form in a high state of purity.This butane, or a part of it, may be suitably condensed under pressureand returned to the liquid stream of original oleflne-containingmaterial to serve as a diluent therefor in the polymerizing step,advantage being taken by this means of the heat capacity of the butanediluent to absorb the heat of the polymerization reaction and preventundue temperature rise during the reaction.

The polymers remaining after the vaporization of the butane andassociated low boiling hydrocarbons may be employed as such or they maybe segregated into various cuts or fractions by ordinary processes ofdistillation with fractionation, according to the viscosity and/orvolatility of the particular product or products desired.

Likewise, the entire polymer product, or any desired fraction or cutthereof, may be subjected to a saturating, non-destructivehydrogenation, at superatmospheric temperature and supera-tmospherlcpressure and in the presence of a suitable hydrogenating catalyst, suchas finely divided catalytic nickel, to prepare completely hydrogenated,stable, colorless, odorless and absolutely tasteless products of highviscosity index and of any desired viscosity and/or volatility.

The entire oleilne polymerizing operation, together with the preliminaryand subsequent purification operations, will be best understood byreference to the attached flow diagrams, which, together with theexplanatory paragraphs below, are descriptive of a preferred embodimentof the process of our invention when the same is carried out to obtainhigh viscosity and high viscosity index polymers, employing abutene-butane fraction recovered from the gases produced in a petroleumconversion or cracking operation of the usual type.

In the drawings, Figure 1 represents diagrammatically a system for thepolymerization of the low boiling or gaseous oleflnes. and Figure 2 frepresents diagrammatically a system for separating unreacted or inertlow boiling hydrocarbons from the produced polymers and for separatingthe whole produced polymer product into such fractions or cuts as may bedesired for particular purposes.

In such a particular embodiment of the process of our invention:

The gases produced in the thermal conversion or cracking of thepetroleum gas oil or residuum are fractionated to remove the greaterpart of the hydrocarbon component of pentane and higher boiling pointand of propane and lower boiling point. Such a fraction may be composed\of the following hydrocarbon ingredients, in which typical proportionsare represented, which proportions, however, vary considerably accordingto the type of oil cracked and according to the character of thecracking operation:

Liquid volume percent Propylene 1.0 Propane 4.0 150 butene 15.0 Butenes1 8: 2 28.0 Butanes 50.0 Pentanes 2.0

In addition to these hydrocarbon ingredients, methyl mercaptan may alsobe present at times for example, a 4 to 16 Baum sodium hydroxidesolution. in suitable amount, is continuously fed from the caustic sodastorage tank 3 through the line 4 to a point near the top of thescrubber 5, suitably also through a distributor plate (not shown). Thequantity of aqueous alkali required to reduce the hydrogen sulfide andmercaptans to an acceptably low concentration varies considerably withthe source of the butanebutene fraction and particularly with the originof the petroleum oil originally subjected to the conversion process. Inthe case of materials obtained from California petroleum, generallyconsidered to be of high sulfur content, we have found that about 0.1volume of 8% sodium hydroxide solution per volume of liquid hydrocarbonmaterial is suflicient to reduce sulfide and mercaptan sulfur to a pointbelow about 0.005% by weight.

Spent or partially spent aqueous caustic soda solution, settled free ofentrained hydrocarbons, is removed from the bottom of the scrubbingtower 5 and the sulfur-free hydrocarbon liquid, settled free ofentrained aqueous liquor, passes from the top of the tower 5, throughline 1, to a drying chamber 8.

The drier 8 is packed with lump anhydrous calcium chloride, periodicallyreplaceable through lines 9 and 9', provided with suitable means forintroducing and removing the solid drying agent (not shown).

The dried hydrocarbon liquid, preferably dried to a degree such that nocloudiness appears when a sample of the liquid is cooled to atemperature of 30 to 40 below zero Fahrenheit, leaves the drying chamberthrough the line l0, and passes into the line Ii and through the coolerI 2.

In the line H the charged olefine-containing hydrocarbon liquid isjoined by a stream of condensed hydrocarbons flashed oil" from theproduced olefine polymers at a later step in the process, discussedhereinbelow, which is recycled into and through the polymerizing chambertogether with the charged olefines in order to aid in the control of thepolymerizing action. Ordinarily this recycled liquid consists largely ofbutane, but it may contain, as well, variable though smaller amounts ofother saturated hydrocarbons and such inconsiderable amounts ofunreacted low boiling olefines as may have passed through the systemwithout polymerization. In a preferred embodiment of the process of theinvention, about three volumes of this recycled butane is employed pervolume of butane-butane" which enters the polymerization system asthrough the line H). In the system represented in Figure 1, thisrecycled butane, in liquid form, is returned through the line l3 and iscooled, together with the incoming stream from line ill, in the coolerl2. Alternatively, a part of the butane-polymer stream leaving the tarsettler i8 (or, more preferably, leaving the filter 2|) may be recycledto and through the polymerization chamber i5, as by the lines l3a, l3,II and I4, in lieu of the hutane flashed ofl at a later step, to serveas an aid in controlling the temperature of the polymerization reaction;such an alternative procedure accomplishes the desired end and efiects aconsiderable heat economy over the recycling of butane itself, asdescribed.

The hydrocarbon liquids are cooled in cooler l2 to about 0 F. and passinto the top of the polymerizing chamber l5 through the line i4.

The size and shape of the reaction chamber [5 may vary considerably,depending upon the degree of completeness of polymerization sought andupon the olefine concentration of the olefinecontaining material. Wehave found, in general, that the polymerization reaction is relativelyrapid, and that for the polymerization of about of the olefinescontained in a charged material of the character hereinaboveexemplified, a yer-- tical tower with an efiective catalyst volume ofabout 0.12 to about 0.16 cubic feet per gallon of the above liquidmixture per hour is of adequate size.

Upon passage downwardly over and through the polymerizing catalyst, inthe reaction chamber IS, the olefines are polymerized to high viscosity,high viscosity index olefinic hydrocarbons, which polymerizationreaction is accompanied by a rise of temperature in the chamber and inthe liquid stream therein. In a typical case, employing a butene-butanefraction composed as tabulated above, admixed with three times itsvolume of recycled butane, the stream enters the chamber through theline H at about 0F. The temperature rises as the earlier and mostsigniflcant polymerization reactions take place, and the temperature ofthe mixed stream leaving the bottom of the reaction chamber through theline H is about 80-100 F.

As the polymerization reaction proceeds, th anhydrous aluminum chloridecatalyst changes slowly from solid form to a mobile liquid, and as thisliquid or spent catalyst appears it flows by gravity to the bottom ofthe reaction chamber and is removed from the chamber, together with thehydrocarbon stream containing .produced polymers, through the line H.

Fresh catalyst is introduced through the line I 6, which is providedwith suitable means for continuous or periodic entry of lump or granularsolid materials (not shown). The quantity of catalyst required to beemployed is found to depend upon the character of the oleflne-containingmaterial introduced, and also upon the degree of completeness of thepolymerizing reaction sought to be accomplished in a single operation;we have found, in general, that for a stock similar to that hereparticularly exemplified, about 0.05 lb. of anhydrous aluminum chlorideper gallon of original oleflne-containing hydrocarbon liquid will causethe polymerization of about 90% of the oleflnes contained therein. Inthe preferred embodiment of the process, in which uniform feed ismaintained in lines It and I3 into the reaction chamber, and uniformtemperature is maintained in the line II, the temperature obtaining inthe line H is a guiding point of observation for the desirability ofreplenishing the supply of fresh catalyst, if the feed of catalyst isnot also kept more or less continuous and uniform.

The mixture of hydrocarbon liquid and mobile spent catalyst leaving thereaction chamber enters a settling vessel l8 through the line H, asshown. The vessel It may be open or unpacked, but may be suitably packedwith high silica rock or other inert material which serves to provideextensive surfaces upon which the liquid particles of mobile sludgecoalesce or agglomerate. By such means the overall size of the settlingchamber is markedly reduced, and clarification of the hydrocarbon streamrendered more easily certain. Spent aluminum chloride sludge,substantially free of entrained hydrocarbons, leaves the bottom of thesettler through line 20, and the substantially completely clarifiedhydrocarbon stream leaves the top of the settler through the line l9 andenters the top of a vessel 2|, packed with an adsorbent earth such as aFlorida clay, charcoal or the like, suitably ground to 30 to 60 meshfineness. Upon passage downwardly through the chamber 2|, all remainingaluminum chloride sludge, and, in addition, all color-forming bodies areremoved by the adsorbent contained therein.

The material employed as adsorbent agent in chamber 2i is periodicallyremoved through line 23 and is replenished through line 22, bothsuitably provided with means for withdrawing and introducing solids ofthe character employed (not shown), or two or more such towers may beemployed in parallel, the stream from line l9 being diverted from one toanother of the towers as the adsorbent material in one of them isdesired to be replaced.

The stream of hydrocarbon liquid leaving the lay filter or percolationchamber 2|, through line 24, is crystal-clear and absolutelywater-white. It consists in greater amounts of inert hydrocarbonsaccompanying the original olefine-containing material employed, togetherwith the butane recycled through line l3, but contain in solution thehigh viscosity, high viscosity index polymers produced in thepolymerizing reaction eifected in chamber l5.

In the typical case here exemplified, the continuous feeding of about840 gallons per hour of liquefied butane-butene fraction composed ashereinabove tabulated (all volumes hereinafter mentioned being referredto as volumes at 60 F.) consume about 42 lbs. per hour of anhydrousaluminum chloride, to produce about 210 gallons per hour of viscouspolymers. In such a typical case, the oily throughput rates in lines I0,l2, I4 and 24, together with the approximate liquid volume percentagecomposition of the streams of each of these points, appear in thefollowing tabulation:

Stream No Stream, gals./hr.@ 50 F.

24 3, 257 Stream. lbs./hr 4.

m r-swap wow-acorn In the polymerizing system here particularlydescribed as a preferred embodiment of our invention, it remains to freethe produced polymers from the inert and unreacted low boiling materialsaccompanying them, and to separate the produced polymers into such cutsor fractions as may be desired, according to the viscosity or volatilityof the olefinic product desired, as well as according to the characterof the saturated, hydrogenated products desired ultimately to beprepared therefrom.

Such a separation system, designed to accompany the polymerizing systemshown in Figure 1, may be conveniently comprised of the severalvaporizing and condensing elements shown in Figure 2.

With reference to Figure 2:

The polymer containing stream discussed above, water-white andcrystal-clear, consisting in major part of liqueflednormally gaseoushydrocarbons and containing the produced polymers in solution, isintroduced into a flash chamber 21, the liquid contents of which areheld at a temperature sufficient to vaporize the butane, pentane andlike low boiling hydrocarbons and cause their removal in vapor form.Steam may conveniently be employed as a vaporizing agent, preferably,however, with closed steam coils rather than by direct introduction intocontact with the hydrocarbon stream; thus steam may enter a set ofheater coils 25 through line 26, as shown, or the said coils may beplaced in the bottom of the flash chamber itself.

Light hydrocarbon vapors are removed from the vaporization vessel 21through the line 28 and condensed in condenser 29, from which a part ofthe condensed butane may be led through line I3 for recycling into andthrough the olefine polymerization chamber (in Figure 1, through linel3, cooler I 2 and line H). The "butane" not employed in the recyclingoperation may be disposed of as desired; obviously it is a highlypurified licuid, substantially free of all non-hydrocarbon impurities.

The polymers, stripped of normally gaseous hydrocarbons, leave the flashstill through line and pass through cooler 3| to storage vessel 32.

The polymers contained in the vessel 32 may constitute the end productof the processor our invention, or, as may be in most cases desirable,these polymers may be separated into various cuts or fractions, eitherfor use as such or for hydrogenation into completely saturated series ofhydrocarbons. v

For a convenient separation into three or more fractions, the polymersmay pass from the vessel 32 through heater 34 and lines 35 and 36 toatmospheric pressure fractionating tower 31,, or. if the entirepolymerization and fractionating systems be made both continuous, thepolymers may pass from the bottom of the flash chamber 21 through lines30 and 38 directly to the fractionating column 31.

In the typical case here particularly exemplifled, from 10 to 15 orthereabouts percent by volume of the whole polymers are found to be ofsubstantially gasoline and kerosene boiling point range. and such aproportion of the whole polyer products is accordingly taken off invapor form from the tower 31; these vapors leave through l ne 38. arecondensed in condenser 39 and are collected in vessel 40, from whichpart of the liquid is returned to the vessel 31 through "w 4|. forrefluxing, and part removed through "n 42 to storage. for admixture withtreated motor fuel, for utilization as solvent, thinner and the l ke. Aswill be obvious, the material is substantially entirely olefinic, andcontains no par- '-fli iic. aromatic or hydroaromatic bodies, and is ofextremely high purity insofar as concerns contamination withnon-hydrocarbon substances.

When saturated by a non-destructive hydrogenation, these gasoline and/orkerosene boiling point fractions are found to be of pleasant odor andare extremely stable to oxidation and/or gum and color formation,distinguishing them from light distillates obtained from naturalpetroleum oils; as a'consequence of this marked stability they leave noresidual odor upon contact with fabrics, etc., and are of high value ascomponents of liquid coating compositions, cleaning fluids and the like.Such hydrogenated products are, moreover, of very high non-detonatingvalue when used alone or in admixture with other hydrocarbons, as motorfuels.

Fractionation of any desired degree is maintained in the tower 31 bysuitable control of reflux and by suitable temperature maintenance atthe base of the tower, as by means of heater 43.

Again, if a polymer product stripped only of relatively volatileoleflnic components, such as those of the gasoline and kerosene boilingpoint range, is desired to be produced, the stream leaving the bottom ofthe tower 31, through line 44, may be cooled and led to storage (notshown).

If further segregation is desired to be made between polymers ofdifferent viscosities or volatilities, however, the stream fromatmospheric pressure tower 31 is led through line 44 to heater 45 andthrough line 46 to reduced pressure distillation and fractionation unit41, where an overhead fraction of light polymers is removed in vaporform through vapor line 48 and a bottoms fraction of heavy polymers isremoved in unvaporized form through line 56. Such a segregation mayobviously be made into any desired pair of components, or furtherfractions may separately be removed, as through line 53 from a suitableliquid trap fractionating column.

at a desired place in the The vapors leaving the tower through the line43 are condensed in condenser 43 and held in container 50, from whichliquid is returned through line 5| to serve as reflux in the tower, andfrom which-the "light polymers are removed to storage through line 52.The heavy polymers leaving in liquid form at line 56 are cooled incooler 51 and lead through line 58 to storage. .An intermediate fractionor cut, if such a out be collected. is cooled in cooler 54 and ledthrough line" to storage.

Any convenient heating means may be employed at the base of the reducedpressure unit 41, such as open steam introduced through line 59, causedto enter through a distributor plate (not shown). Likewise, anyconvenient means for maintaining reduced pressure in the column 41 maybe employed, such as a vacuum pump, a steam jet or water let (notshown).

Obviously the particular system employed in segregating the wholepolymer products into desired components is a function of the characterof the components sought to be recovered, and the system hereexemplified is intended to serve only as a particular embodiment of sucha system.

A. P. I. Gravity, 33.7"

Viscosity, 1180 Seconds Saybolt at 100 F.

Viscosity, 103 Seconds Saybolt at, 210 F.

Viscosity Index, 105 (By Dean & Davis System, Chemical & MetallurgicalEngineering, Vol. 36, Pages 618-9, 1929).

Viscosity-gravity constant, 0.76 (By Ferris et al.

system, Ind. Eng. Chem, 23, 753, 1931).

These polymers, when led to column 31 for the removal of gasoline andkerosene boiling point stocks, produce about a 10 volume percent yield,in line 42 of light oleflnes boiling between about 250 and about 500degrees F., when the vapor line temperature in 38 is maintained at 300F. and the temperature in the bottom of the column 38 is held at about550 F.

The passage of the bottoms from column 31 through reduced pressurecolumn 41 causes the separation of the polymers into further fractionsas follows:

Temperature a 48, F 450 Temperature at 56, F 570 Pressure in '47, inchesmercury absolute 1.4

Light Polymers, Line 52:

Yield, gallons per hours 116 Gravity, A. P. I 374 Viscosity at 210 F 55Heavy Polymers, Line 58:

Yield, gallons per hour 73 Gravity, A. P. I 25.5 Viscosity at 100 F172,000 Viscosity at 210 F 3,000 Viscosity Index 107 Viscosity-gravityconstant 0.71

In further particularization of certain signifl cant features of theforegoing polymerization process:

I. Eflect of presence of sulfur compounds As noted hereinabove, the lifeof an aluminum chloride catalyst has been found to be remarkably andunexpectedly shortened if substantially all sulfur compounds are notremoved from the olefine-containing material prior to contact with thecatalyst.

For example, in polymerization reactions designed to determine the lifeof anhydrous aluminum chloride as catalyst, we have found that thepresence of 1.3% of hydrogen sulfide by weight allowed the formation of1.0 gallon of propylene polymers per pound of completely spent aluminumchloride, when the polymerization reaction was carried out at 70 F. withthe propylenecontaining hydrocarbon fraction held in liquid phase. Underthe same conditions and from the same propylene-containing fraction, butafter the complete removal of hydrogen sulfide by careful scrubbing withaqueous sodium hydroxide holution, 3.7 gallons of propylene polymerswere produced per pound of completely spent catalyst.

Again, a butane-butane fraction such as that described above inconnection with a preferred embodiment of our invention, containingabout 0.52% by weight of methyl mercaptan, contacted in liquid phasewith anhydrous aluminum chloride to complete exhaustion, produced ayield of 2.2 gallons of butene polymers per pound of catalyst, thepolymerization reaction in this case being maintained at 100 F. Underthe same conditions and from the same butane-butane stock, but aftercomplete removal of mercaptans by careful treatment with plumbitesolution followed by the addition of elemental sulfur and carefulvaporization of hydrocarbons from the produced disulfides, 18.3 gallonsof polymers were obtained per pound of completely spent catalyst.

Over and above the effect of the presence of sulfur compounds on thelife of the polymerizing catalyst, sulfur compounds have a marked effecton the consumption of the hydrogenation catalyst, such as finely dividedcatalytic nickel, used to hydrogenate part or all of the producedolefine polymers. Thus it appears that sulfur compounds are not entirelyremoved by reaction with the polymerization catalyst, in spite of thefact that the length of life of the polymerization catalyst isremarkably shortened by their presence; on the contrary, some at leastof the sulfur compounds are polymerized, it allowed to be present, tohigher boiling sulfur-containing compounds, difilcult or impossible toremove from the produced olefine polymers after their formation. Thesesulfur compounds, if allowed to form and become a component of theviscous polymer mixture, decrease in many cases the number of servicesto which the polymers may be put, and, in addition, cause theconsumption of markedly increased amounts of catalytic nickel necessaryto be used in a saturating, non-destructive hydrogenating reaction. Forexample, even so small a quantity as 0.005% by weight of either hydrogensulfide or mercaptan sulfur in the original olefine-containing materialhas been found to be of effect on the quantity of nickel catalystrequired to hydrogenate the polymers prepared in accordance with theprocess of this invention.

Accordingly, the substantially complete removal of all sulfur compounds,prior to the polymerization steps of the process, is a particularfeature of our invention.

1!. Eflect 0] presence of water Likewise, as noted hereinabove. thepresence of even small quantities of water in the olefinecontainingmaterial passing to the polymerization reaction chamber is carefullyavoided. The major part of even that dissolved water which is held inhomogeneous solution at ordinary temperatures in a liquefied sourcematerial is desirably removed, as by the means hereinabove specified.

Small amounts of water have been found to have an appreciable effect onthe length of life of the polymerization catalyst, but over and abovesuch effect is the fact that small quantities of chlorinatedhydrocarbons are produced by virtue of the formation of hydrochloricacid in the polymerization chamber and the interaction of hydrochloricacid and olefinic polymerized bodies, whereby the utility of the variousviscous polymers is lessened for many purposes, and the fact that suchchlorinated hydrocarbons, if allowed to be formed, have been found tomarkedly increase the consumption of the catalytic material such asfinely divided catalytic nickel, employed to saturate the olefinichydrocarbons in the production of paraflinic products of high viscosityand high viscosity index.

Further, the presence of water is carefully avoided at all such stepsand places in the system as contain any aluminum chloride sludge orreaction products other than strictly hydrocarbon bodies: first, sincesuch products hydrolyze upon contact with water to form certainoil-soluble bodies of detrimental effect to the color of the ultimatelyproduced olefine polymers and hydrogenated parafllnic oils; second,since the aluminum hydroxide also formed is only very difflcultlyfilterable or otherwise completely removable. Thus all contaminationwith water or steam is rigidly guarded against in the sludge settlingvessels, clay or other adsorbent filters or percolation chambers, andthe like. After complete removal of such sludge, water or steam may beallowed to come into contact with the hydrocarbon bodies, withouthazard.

Accordingly, the substantially complete removal of water and the rigidexclusion of water or steam, prior to and during the polymerizationreaction and at all points prior to complete removal of aluminumchloride sludge, is a particular feature of our invention.

III. Eflect of concentration of oleflnes in the polymerization reactionmixture and eflect of temperature of polymerization reaction Thetemperatures maintained during the polymerization reaction, as well asthe concentration of low boiling olefines in the olefine-containingreaction mixture undergoing polymerization, and also the relativeproportions of normal and iso olefines in the olefine-containing mixtureundergoing polymerization, have a material effect upon the viscosity andthe viscosity index of the polymers produced in carrying out the processof our invention. The effect of each of these several variables isseparately determinable, and the conditions obtaining in thepolymerization system may be regulated to take advantage of each ofthese separate variables, according to the olefinecontaining sourcematerials available and according to the character of the productsultimately desired. Although separate, the effects of these variablesare interlocking, as will be apparent from a careful consideration ofthe results obtained in the several particular exemplifying runs shownbelow, chosen to bring out such eifects, separately and together:

(a) They are of inordinately high viscosity index, as compared with theviscosity indices of Example l 2 3 4 Temperature oireaction, F...Butane-containing stream to reaction chamber:

Vol. percent isobutene Vol. percent normal butenes. Vol. percent totalbuteues.. Characteristics oi produced polymers:

mm. mercury ressure- Vls. 100 I Vis. 210F Viscosity index Topped at 420F. and 50 mm. mercur pressure- Vis. 100 F Vis. 210 it-.- Viscosity indexIn the examples tabulated above, substantially complete polymerizationof all. butenes charged was obtained.

A careful consideration of the results obtained in the runs tabulatedabove leads to the following general conclusions:

1. If the olefine-containing source material is of very low olefinecontent, or if the stream entering the polymerization reaction chamberbe so diluted with saturated hydrocarbons as to be of very low olefinecontent, the temperature of the polymerization reaction must bemaintained low if high viscosity index polymers are desired to beproduced (compare runs 1, 2 and 3 and runs 5, 6 and 7).

2. If the olefine-containing source material, or the olefine-containingstream entering the polymerization reaction chamber, is of fairly higholefine content, the temperature of the polymerization reaction may bequite high and a high viscosity index product nevertheless be obtained(see run 1), but the lowering of the temperature of the polymerizationreaction causes an increase in the viscosity index of the product evenin that event (compare runs 2 and 4).

3. The substantial absence of isobutene from the olefine-containingmaterial originally employed decreases somewhat the viscosity index ofthe polymers ultimately obtainable (see run 10 and compare run 8) Fromthe above considerations read in connection with the tabulation, it willbe obvious that the conditions chosen for the carrying out of thepolymerization reaction may be selected so as to obtain a variety ofpolymer products, as desired, and that the several separate eflectivevariables may be adapted to each other to provide a set of conditionssatisfactory with respect to the particular olefine-contalning sourcematerial most conveniently and inexpensively obtainable, according tothe character of the products ultimately desired to be producedtherefrom.

Accordingly, the suitable choice of the conditions of temperature and ofolefine content of the hydrocarbon mixture undergoing polymerization, asdetermined by the character of the products desired and in accordancewith the particular nature of the olefine-containing source materialemployed, is a particular feature of our invention.

In characterizing, generally, the polymers produced by the practice ofthe process of our invention as hereinabove particularly described, wemay note the following:

any product heretofore obtained from an isobutene-normal butenepolymerization reaction; thus they may be of at least 60 to 70 viscosityindex, if desired, and are in many cases above 100 viscosity index, ifdesired;

(b) They are absolutely water-white and crystel-clear;

They are of somewhat higher volatility than products of correspondingviscosity prepared by polymerizing oleflnes of 10, 12 and higher carbonatoms per molecule;

(it) They are completely free of wax or of wax cloud when cooled to aslow as 1'00 F.;

(e) They depolymerize, that is, they decompose, at somewhat lowertemperature than do products of corresponding viscosities prepared bypolymerizing oleflnes of 10, 12 and higher carbon atoms per molecule;

(f) They are completely olefinic in compositron, and contain no aromaticor hydroaromatic cyclic bodies:

(9) They contain substantial proportions of very high molecular weighthydrocarbons, nondistillable without decomposition;

(h) They are oily viscous liquids, rather than of plastic character, asare for example, those strictly isobutene polymers prepared by the slowpolymerization of pure isobutene at 100F. or thereabouts;

(i) Their viscosity at 210 of 40 to 10,000 seconds Saybolt ing to thefraction or out under consideration, rather than of the order of1,000,000+ seconds Saybolt Universal at 210 F., as are the strictlyisobutene polymers prepared by the slow polymerization of pure isobuteneat -100 F. or thereabouts.

In characterizing, generally, the saturated products prepared bycompletely saturating the olefinic viscous polymers of our invention, asby a non-destructive hydrogenation reaction, we may note the following:

(7') They correspond to those properties of the olefinic hydrocarbonsparticularly identified F. is of the order above under paragraph (a),(b), (c), (d), (g),

(h) and (i), and in addition;

(it) They are completely lacking in all taste and odor, even when warmedto body temperature or somewhat above.

Universal, accord (I) They have a viscosity-gravity constant of below0.78, as the term viscosity-gravity constant is employed for example, byHill and Coats in Industrial 8: Engineering Chemistry, volume 20, page641 (1928) and by Ferris, Berkhimer & Henderson in Industrial &Engineering Chemistry, volume 23, page 753 (1931):

(m) The viscosity of the viscous oleiine polymers is substantiallyunchanged upon hydrogenating them; the viscosity-gravity constants ofthe hydrogenated products are lower than those of the correspondingentirely oleflnic polymers; the viscosity-gravity constant decreaseswith increasing viscosity, both in the oleflnic and in the hydrogenatedproducts.

As will be apparent to one skilled in the art, these oleilne polymersand their saturated analogs are adaptable to a wide variety of uses,among which we may mention: their suitability as gear and motor oils,either alone or in admixture with reiined naturally occurring petroleumoils; their suitability in raising the viscosity index of refined motoroils of lower viscosity index, by blending them therewith in suitableproportions; as technical or medicinal white oils; as lubricants forrefrigerating machinery; etc. The novel and unusual properties of thecompositions oi! our invention, as the same are listed hereinabove, willindicate the variety of uses to which they may be put, many 01' whichare not entirely satisfactorily fulfilled by naturally occurring mineraloils or the synthetic hydrocarbon oils heretofore available.

While we have not hereinabove particularly discussed the means ofeffecting complete saturation of the entirely oleilnic products preparedin accordance with our invention, we may observe, in general, that anordinarily acceptable non-destructive hydrogenation system as the sameis employed, for example, in the partial or complete hydrogenation ofthe edible vegetable oils, is suitable tor the complete hydrogenation ofour viscous oleflne polymers and the production 01 entirely parafliniccompositions of the characteristics enumerated above. This hydrogenationreaction is ordinarily carried out with the polymers in liquid phase,and catalytic nickel is suitably employed as hydrogenation catalyst; thetemperature oi the reaction may be between 200 F. and 450 F., generallyabout 350' F., and the hydrogen pressure imposed upon the mixtureundergoing hydrogenation may be from about 60 to about 500 pounds gauge,suitably about 150 pounds gauge. We find, in general, that theparticular conditions obtaining during the hydrogenation reaction do notmaterially afl'ect the character or properties of the produced saturatedliquid hydrocarbons, but may note that the quantity of hydrogenationcatalyst employed is usually somewhat greater than is required tocompletely hydrogenate the edible vegetable and the like natural oils.

Although certain specific temperatures, concentrations, conditions andoperations have been described hereinabove in detail in connection withthe practice 0! the processes of our invention, and although certainspecific compositions, both oleflnic and paraflinic, have been describedhereinabove as representative of the products or our invention, it is tobe understood that such conditions, operations, and compositions aremerely illustrative of the processes and of the products of ourinvention and are not to be taken as limiting the same. Numerous changesand modifications may be made in both the processes and the products aswill become apparent to those skilled in the art, and all such changesand modiflcations as come within the scope oi the appended claims areembraced thereby.

We claim:

1. The process of producing synthetic hydrocarbon oils of high viscosityindex and of higher than 40 seconds Saybolt Universal viscosity at 210F., having the properties of viscous liquids rather than of plasticsolids, which comprises bringing in contact with anhydrous aluminumchloride, in liquid phase, an-initial hydrocarbon material consistingsubstantially entirely of hydrocarbons of 3, 4 and 5 carbon atoms permolecule and consisting of hydrocarbons of 4 carbon atoms per moleculein major part, the said initial. hydrocarbon material containing bothnormal oleflnes and iso-olefines and being accompanied by correspondingsaturated aliphatic hydrocarbons, at a temperature not above about 120F. but sumciently high to cause the polymerization of both normaloleflnes and iso-oleilnes, separating the produced polymerized oleflnesand accompanying unpolymerized oleflnes from the anhydrous aluminumchloride and hydrocarbons associated with it in loose chemicalcombination and then separating .the produced oleiine polymers fromunpolymerized hydrocarbons.

2. The process of producing synthetic hydrocarbon oils of high viscosityindex and or higher than 40 seconds Saybolt Universal viscosity at 210F., having the properties of viscous liquids rather than of plasticsolids, which comprises bringing in contact with anhydrous aluminumchloride as polymerizing catalyst, in liquid phase, an initialhydrocarbon material consisting substantially entirely or normalbutenes, isobutene and butane, at a temperature not above about 120 F.but sufllciently high to cause the polymerization of both the normalbutenes and iso-butene, separating the produced butene polymers andbutane from the polymerizing catalyst and associated hydrocarbons inloose chemical combination therewith and then separating the producedpolymers from the butane.

3. The process of producing synthetic hydrocarbon oils of high viscosityindex and of higher than 40 seconds Saybolt Universal viscosity at 210F., having the properties of viscous liquids rather than of plasticsolids. which comprises substantially completely removing all sulfurcompounds from a hydrocarbon mixture consisting substantially entirelyof hydrocarbons of 3, 4 and 5 carbon atoms per molecule and consistingof hydrocarbons o! 4 carbon atoms per molecule in major part, the saidinitial hydrocarbon mixture containing both normal oleflnes andiso-olefines and being accompanied by corresponding saturated aliphatichydrocarbons, bringing the sulfur-free hydrocarbon mixture in contactwith anhydrous aluminum chloride, in liquid phase, and at a temperaturewithin the range 0 F. to 120 F., to cause the polymerization of bothnormal oleflnes and iso-oiefines, separating the produced polymerizedoleflnes and accompanying unpolymerized hydrocarbons from the anhydrousaluminum chloride and the hydrocarbons associated with it in loosechemical combination, and then separating the produced oleflnes polymersfrom unpolymerized hydrocarbons.

4. A process of producing synthetic hydrocarbon oils of high viscosityindex and of higher than 40 seconds Saybolt Universal viscosity at 210R, which comprises cooling and liquefying a hydrocarbon materialconsisting substantially entirely of hydrocarbons of 3, 4 and 5 carbonatoms per molecule and consisting of hydrocarbons oi 4 carbon atoms permolecule in major part, the said hydrocarbon material containing bothnormal olefines and iso-olefines and being accompanied by correspondingsaturated aliphatic hydrocarbons, passing the cooled hydrocarbonmaterial in liquid phase downwardly through a reaction zone containinganhydrous aluminum chloride to cause the formation of viscous polymers,maintaining the said reaction zone at a temperature sufilciently high tocause the polymerization of both normal 'and iso-oleflnes but not aboveabout 120 F., withdrawing produced polymers, unpolymerized hydrocarbonsand aluminum chloride sludge from the reaction zone, separating bygravity the major part of the aluminum chloride sludge, passing producedpolymers and unpolymerized hydrocarbons in contact with an adsorbentagent to completely remove all traces of aluminum chloride sludge andseparating the produced olefine polymers from unpolymerizedhydrocarbons.

5. A process of producing saturated hydrocarbon oils of high viscosityindex and of higher than 40 seconds Saybolt Universal viscosity at 210F., having the properties of viscous liquids rather than of plasticsolids, which comprises bringing in contact with anhydrous aluminumchloride as polymerizing catalyst, in liquid phase and at a temperaturesufilciently high to cause the polymerization of both normal oleflnesand iso-olefines but not higher than about 120 F., an initialhydrocarbon material consisting substantially entirely of hydrocarbonsof 3, 4 and 5 carbon atoms per molecule and consisting of hydrocarbonsof 4 carbon atoms per molecule in major part, the said initialhydrocarbon material containing both normal oleilnes and isoolefines andbeing accompanied by corresponding saturated aliphatic hydrocarbons, tocause the polymerization of both normal olefines and isoolefines,separating the produced polymerized olefines and accompanyingunpolymerized hydrocarbons from the polymerizing catalyst and associatedhydrocarbons in loose chemical combination therewith, separating theproduced olefine polymers from unpolymerized hydrocarbons andhydrogenating the olefine polymers by catalytic hydrogenation of thenon-destructive type.

6. A process of preparing high molecular weight polymerization productshaving the properties of viscous lubricating oils-rather than of plasticsolids, comprising cracking a hydrocarbon oil to produce a mixture ofnormally, liquid and gaseous products, separating from said crackedproducts the fraction consisting substantially entirely of normalbutenes, iso-butene, and butane, treating said fraction in liquid phasewith aluminum chloride as the polymerizing agent at a temperaturebetween about 32 F. and 100 F. and separating from the resulting mixturethe said high molecular weight polymerization products.

7. High molecular weight polymerization products having the propertiesof viscous lubricating oils rather than of plastic solids, preparedaccording to the process which comprises: cracking a hydrocarbon oil toproduce a mixture of normally liquid and gaseous products, separatingfrom said cracked products the fraction consisting substantiallyentirely ofnormal butenes, iso-butene and butane, treating said fractionin liquid phase with aluminum chloride as the polymerizing agent at atemperature between about 32 F. and 100 F., and separating from theresulting mixture the said high molecular weight polymerization prod--ucts.

8. A process of producing synthetic hydrocarbons possessing theproperties of viscous liquid oils rather than of plastic solids, of highviscosity index and of a viscosity above 40 seconds Saybolt Universal at210 F., from a liquefied normally gaseous hydrocarbon materialconsisting substantially entirely of normal butenes, iso-butene andbutane, which comprises cooling the said liquefied hydrocarbon materialto a subatmospheric temperature and passing it in liquid phase throughan anhydrous aluminum chloride polymerization zone maintained at atemperature suflicient to cause the polymerization of bothnormalvbutenes and iso-butene but below about 80 F., to cause theformation of viscous butene polymers, removing substantially allaluminum chloride and aluminum chloride sludge, separating unpolymerizednormally gaseous hydrocarbons from the produced polymers, and coolingand recycling a part of the unpolymerized hydrocarbons, in liquidphase," into and through the said polymerization zone together withfresh liquefied normal butenes, iso-butene and butane in order tomaintain the temperatures obtaining in the polymerization zone at atemperature below about 80 F.

9. A process of producing synthetic hydrocarbons possessing theproperties of viscous liquid oils rather than of plastic solids, of highviscosity index and of a viscosity above 40 seconds Saybolt Universal at210 F., from a liquefied normally gaseous hydrocarbon materialconsisting substantially entirely of normal butenes, iso-butene andbutane, which comprises cooling the said liquefied hydrocarbon materialto a subatmospheric temperature and passing it in liquid phase throughan anhydrous aluminum chloride polymerization zone maintained at atemperature sufficient to cause the polymerization of both normalbutenes and iso-butene but below about 40 F., to cause the formation ofviscous butene polymers, removing substantially all aluminum chlorideand aluminum chloride sludge, separating unpolyrnerized normally gaseoushydrocarbons from the produced polymers, and cooling and recycling apart of the unpolymerized hydrocarbons, in liquid phase, into andthrough the said polymerization zone together with fresh liquefiednormal butenes, iso-butene and butane in order to maintain thetemperatures obtaining in the polymerization zone at a temperature belowabout 40 F.

10. A process of producing synthetic hydrocarbons possessing theproperties of viscous liquid oils rather than of plastic solids, of highviscosity index and of a viscosity above 40 seconds Saybolt Universal at210 F., from a liquefied normally gaseous hydrocarbon materialconsisting sub-. stantially entirely of normal butenes, iso-butene andbutane, which comprises cooling the said liquefied hydrocarbon materialto a subatmospheric temperature and passing it in liquid phase throughan anhydrous aluminum chloride polymerization zone maintained at atemperature within the range 0 F. to 80 F. to cause the formation ofviscous butene polymers of high viscosity index, removing substantiallyentirely all aluminum chloride and aluminum chloride sludge, separatingunpolymerized normally gaseous hydrocarbons from the produced polymers,and cooling and recycling 9. part of the unpolymerized hydrocarbons inliquid form into and through the polymerization zone together with freshliquefied normal butenes, iso-butene and butane in order to maintain thetemperatures obtaining in the polymerization zone within the range 01''. to F.

11. A synthetic hydrocarbon oil composed substantially entirely oracyclic hydrocarbons and containing substantially no aromatic orhydroaromatic hydrocarbons, having a viscosity index oi above 60, aviscosity at 210? 1''. within the range 40 to 10,000 seconds SayboltUniversal, a viscosity-gravity constant below 0.78, having thecharacteristics of a viscous liquid rather than of a plastic solid,being substantially tree 0! wax and wax cloud at temperatures as low asl00 F., prepared by the process which comprises: bringing in contactwith anhydrous aluminum chloride as polymerizing catalyst an initialhydrocarbon material consisting substantially entirely of hydrocarbons0! 3, 4 and 5 carbon atoms per molecule and consisting of hydrocarbonsof 4 carbon atoms per molecule in major part, said initial hydrocarbonmaterial containing both normal oleilnes and iso-oleiines and beingaccompanied by corresponding saturated aliphatic hydrocarbons, in liquidphase and at a temperature below about 120 F. but sumcient to cause thepolymerization of both normal oleflnes and isooleiines, separating theproduced polymerized olefines together with accompanying unpolymerizedoleflnes and saturated aliphatic hydrocarbons from aluminum chloridesludge prior to any contact 01 water therewith, and then separating theproduced oleilne polymers from unpolymerized hydrocarbons.

12. A synthetic hydrocarbon oil composed substantially entirely ofacyclic hydrocarbons and containing substantially no aromatic orhydroaromatic hydrocarbons, having a viscosity index of about 100, aviscosity at 210' 1". within the range of 300 to 10,000 seconds SayboltUniversal, a viscosity-gravity constant below 0.78, having thecharacteristics of a viscous liquid rather than 0! a plastic solid,being substantially tree 0! wax and wax cloud at temperatures as low asF., prepared by the Process which comprises: bringing in contact withanhydrous aluminum chloride as polymerizing catalyst an. initial hydrocarbon material consisting substantially entirely of normal butenes,iso-butene and butane, said initial hydrocarbon material containingpreponderant amounts oi butane, in liquid phase and at a temperaturebelow about 80 F. but suilicient to cause the polymerization of bothnormal oleflnes and iso-oleiines, separating the produced polymerizedoleflnes together with accompanying unpolymerized oleflnes and saturatedaliphatic hydrocarbons irom aluminum chloride sludge prior to anycontact of water therewith, separating the produced oleflne polymersfrom unpolymerized hydrocarbons, and then removing by vaporizationsuiiicient oi the more volatile polymers to provide a residue having aviscosity at 210' 1". or more than 300 but less than 10,000 secondsSaybolt Universal.

13. A synthetic hydrocarbon oil composed sub- -aromatic hydrocarbons,having a viscosity index oi above 100, a viscosity at 210 F. oi! about3,000

seconds Saybolt Universal, a viscosity-gravity 5 constant below 0.78,having the characteristics 0! a viscous liquid rather than oi a plasticsolid, being substantially free 01' wax and wax cloud at temperatures aslow as l00 F., prepared by the process which comprises: bringing incontact with anhydrous aluminum chloride as polymerizing catalyst aninitial hydrocarbon material consisting substantially entirely of normalbutenes, iso-butene and butane, said initial hydrocarbon materialcontaining preponderant amounts of butane, in liquid phase and at atemperature below about 80 F. but suiiicient to cause the ploymerizationor both normal olefines and iso-oleflnes, separating the producedpolymerized oleflnes together with accompanying un- 2 polymerizedoleflnes and saturated aliphatic hydrocarbons from aluminum chloridesludge prior to any contact of water therewith, separating the producedolefine polymers from unpolymerized hydrocarbons, and then removing byvaporizat on 2 suilicient or the more volatile polymers to provides aresidue having a viscosity at 210 F. of about 3,000 seconds SayboltUniversal.

14. A synthetic hydrocarbon oil composed substantially entirely ofacyclic saturated paraiilnic 3 hydrocarbons and containing substantiallyno aromatic or hydroaromatic hydrocarbons, having a viscosity index ofabove 100, a viscosity at 210 F. within the range 300 to 10,000 secondsSaybolt Universal, 9. viscosity-gravity constant 3 below 0.78, havingthe characteristics oi! a viscous liquid rather than of a plastic solid,being substantially free oi wax and wax cloud at temperatures as low as-100 F., prepared by the process which comprises: bringing in contactwith anhydrous aluminum chloride as polymerizing catalyst an initialhydrocarbon material consisting substantially entirely of normalbutenes, iso-butene and butane, said initial hydrocarbon materialcontaining preponderant amounts of butane, in liquid phase and at atemperature below about 80 F. but sumcient to cause the polymerizationof both normal oleiines and iso-olefines, separating the producedpolymerized olefines together with accompanying unpolymerized olefinesand saturated aliphatic hydrocarbons from aluminum chloride sludge priorto any contact of water therewith, separating the produced oleflnepolymers from unpolymerized hydrocarbons, removing by vaporizationsuillcient o! the more volatile polymers to provide a residue having aviscosity at 210 F. of more than 300 but less than 10,000 secondsSaybolt Universal, and completely hydrogenating the olefine polymers byhydrogenation of the saturating non-destructive type.

MELVIN M. HOLM. ARTHUR L. LYMAN. MARVIN F. MILLER.

CERTIFICATE OF CORRECTION. Patent No. 2,22h,5h9- December 10, 19!;0.

' MELVIN n. HOLH, ET AL.

It is hereby certified that error appears in the printed specificationof the above numbered patentrequiring correction as follows: Page 5,first column, line 15, for iso butane" read --iso butene--; and that thesaid Letters Patent should be read with this correction therein that thesame may conform to the reccrd of the case in the Patent Office.

Signed and sealed this 11th day of February, A. n. 19m.

Henry Van Arsdale, (Seal) Acting Commissioner of Patents.

